It was the actress' fifth visit to Iraq, but first since Islamic State were forced from the city in one of the bloodiest battles of the 21st century.

"There are bodies in this rubble that stay here," Ms Jolie said.

"You can smell the bodies and some of them have family members that are here and they are unable to move them.

"This is the worst devastation I have seen in all my years with UNHCR."

Jolie is a United Nations special envoy. Picture: UNHCR (Reuters)It was Jolie's fifth visit to Iraq. Picture: UNHCR (Reuters)The country's second-largest city was ravaged in fighting between ISIS and Iraqi forces. Picture: 9NEWS (Reuters)